Saturday, May 21, 2016


Disclaimer: Except for the direct quotes following, the content of this posting is completely my speculation, and neither Dietrich Stout or Scientific American can be held responsible for any mistakes or errors. 

We rock art enthusiasts have long believed that the beginnings of rock art indicated a certain level of intellectual development in our human ancestors. Now, a remarkable article in the April, 2016, Scientific American (Vol. 314, No.  4), by Dietrich Stout titled Cognitive Psychology/Tales of a Stone Age Neuroscientist, suggests that learning to make rock art may have been an important factor in that intellectual development.

Oldowan chopper, Wikimedia.
Public domain.

Acheulian hand axe, Spain.
Wikimedia. Public domain.

Stout reported that he and his collaborators learned to knap stone, to recreate Oldowan type stone tools (2.5 to 1.2 million years BP), and Achulean type stone tools (1.6 million to 200,000 years BP). This process of learning to knap stone, and then the production of the tools, proceeded with a series of brain scans to attempt to identify any neural changes.

            "We suspected that learning to knap would also require some degree of neural rewiring. If so, we wanted to know which circuits were affected. If our idea was correct we hoped to get a glimpse of whether toolmaking can actually cause, on a small scale, the same type of anatomical changes in an individual that occurred over the course of human evolution.
            The answer turned out to be a resounding yes: practice in knapping enhanced white matter tracts connecting the same frontal and parietal regions identified in our PET and MRI studies, including the right inferior frontal gyrus of the prefrontal cortex, a region critical for cognitive control. The extent of these changes could be predicted from the actual number of hours each subject spent practicing - the more someone practiced, the more their white matter changed." (Stout 2015:33-34)

Rhinos, Chauvet Cave.
 Wikimedia. Public domain

Lion Man, Hohlenstein-Stadel.
Public domain.

But, what excited me more upon reading this is that the creation of the two tool types left detectable differences in the brain changes. This leads me to what I believe to the reasonable conclusion that the creation of any two types of object would have different effects upon the development of the brain of the creator. In other words, cave painting and Paleolithic bone and ivory carving would have enhanced the development of the brains of their creators, and thus I think I can safely assume that this would also apply to the act of creating petroglyphs and pictographs. That the creation of this rock art not only signaled a certain level of cognitive development, it actually contributed to that development, and the different types of creations made different contributions to that development.

"The results of our own imaging studies on stone toolmaking led us recently to propose that neural circuits, including the inferior frontal gyrus, underwent changes to adapt to the demands of Paleolithic toolmaking and then were co-opted to support primitive forms of communication using gestures and, perhaps, vocalizations. This protolinguistic communication would then have been subjected to selection, ultimately producing the specific adaptations that support modern human language." (Stout 2016:35)

Westwater Creek, Bookcliffs,
Grand County, Utah.
Photograph: Peter Faris,
September, 1981.

Sproat Lake, Vancouver Island,
British Columbia, Canada.
Photograph: Peter Faris, 1995.

So, if all this is really true, by extension, I believe we can postulate that the creation of this art influenced the creation of culture, and the form or type of art created determined the type of that influence. In effect, this seems to imply that the act of painting pictographs would influence the development of the brain in a different way than the carving of a petroglyph. This suggests that we may someday be able to analyze the art to predict the type of culture that produced it, and vice versa; that we may be able to analyze a culture and predict the kind of art it produced. In any case I will be eagerly waiting for further elaboration of this truly exciting investigation, and I hope that it will lead to proof that rock art influenced the development of intelligence, language, and culture. 


Stout, Dietrich
2016    Cognitive Psychology: Tales of a Stone Age Neuroscientist, pages 28-35, Scientific American, Volume 314, Number 4, April, 2016.


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